BLACKSBURG, Va. — By his words and actions, Seung-Hui Cho is a familiar character to researchers who have studied the previous shootings in the nation's schools.

Based on emerging accounts of his behavior before his deadly attack at Virginia Tech, Cho exhibited three characteristics that the experts say are common among school shooters:

He didn’t “just snap” but instead acquired the weapons weeks earlier.

He was considered a threat by others, even though he didn’t make any explicit threats.

Fellow students and teachers raised concerns about his behavior.

Cho caused a great deal of concern on the Virginia Tech campus before Monday's mass shooting, even being committed to a mental health facility for a day or two in 2005 after he made a second unwanted contact with female students, campus officials said Wednesday. His writings and behavior in class alarmed other students and teachers. His roommates heard him talk of suicide.

But because he didn’t threaten to harm anyone, university officials said, there was little more they could do.

Behavior matches pattern
That's been the pattern in most previous school attacks in the U.S., according to a landmark study in 2002 by the U.S. Secret Service. Researchers looked at 37 school shootings and interviewed 10 of the shooters themselves.

In more than 3 out of 4 school shootings, the attacker had made no threat against the schoolteachers or students. But most attackers engaged in some behavior prior to the incident that caused others concern or indicated a need for help. The attackers posed a threat even though they hadn't made a threat.

Schools can do a lot more to deal with such concerns, said one of the authors of the study.

"The notion that a concerned teacher who tries to get someone to counseling and that there are no other options if the student refuses to go — that seems much too limited," one of the report’s co-authors, psychologist Robert A. Fein, told MSNBC.com on Wednesday. He has consulted with federal agencies on targeted violence, including terrorism, school shootings and workplace violence.

"I understand that students in college are not high school kids," Fein said, "but schools should be able to do better than that. This is not to cast blame on anyone. There's no cookie-cutter solution, and there probably are lots of 'right ways,' but the notion of having a team that can gather and examine information and determine 'we may have a problem here' and then work to figure out what to do, or ask others, or keep working on it, still makes sense to me."

Virginia Tech officials described a long chain of events preceding Monday's shooting and expressed frustration that their systems weren't set up to deal with a student like Cho, who had not made a threat or committed a crime. Since his erratic behavior did not cross those thresholds, they said they could do nothing more than recommend he receive counseling.

Cho came to authorities' attentionThe officials said that Cho had come to their attention several times before Monday’s shooting:

On Nov. 27, 2005, a female student told campus police that she had received unwanted phone calls and visits from Cho, campus police said. She declined to press charges and told police that Cho was "annoying" rather than threatening. Police referred Cho to the campus disciplinary system; the university won't say what happened next, citing privacy laws. Even Cho's parents, they said, could not be told the results.

In December 2005, a second female student told campus police that she received unwanted instant messages from Cho. She said no explicit threat was made, but she asked police to tell him to have no further contact with him. (Neither of these female students was among this week's victims, campus officials said.)

On the same day as the second complaint, a person told campus police that they were concerned that Cho might be suicidal. Police did not identify the person, but two of Cho's roommates have said they communicated this concern to the resident advisers in the dorm and to campus police. Campus police spoke with Cho, and asked him to speak with a counselor. He was sent to New River Community Services, a counseling center off campus, and then was detained at St. Alban's, a mental health center near Radford, Va. Police said they don't know details of his treatment at New River, and on Wednesday they applied for a search warrant for his medical records. The officials didn't say how long he was treated there, but his roommates have said in interviews that he was gone for one to two nights. If his detention was involuntary, it should have shown up on background checks when he bought two guns in the 10 weeks before the shooting, officials said.

Cho's writings also caused concerns. Teacher and poet Nikki Giovanni said other students were afraid to come to class with him, because of his sullen demeanor, and because he was taking photos of other students in class. She tried to talk with Cho, and sought help from her department chair, who tried to talk Cho into going to counseling.

Those behaviors fit the "profile" of a school shooting. That's not a profile of a certain type of student — school shooters have been of many ethnicities, family backgrounds and academic standing. But experts say there is a pattern of actions that typically precede an attack.

Seldom impulsive actsForemost is that incidents of targeted violence at school are rarely sudden, impulsive acts, the experts say.

"Students who engaged in school-based attacks typically did not 'just snap' and then engage in impulsive or random acts of targeted school violence," the Secret Service researchers wrote. "Instead, the attacks examined under the Safe School Initiative appeared to be the end result of a comprehensible process of thinking and behavior: behavior that typically began with an idea, progressed to the development of a plan, moved on to securing the means to carry out the plan and culminated in an attack. This is a process that potentially may be knowable or discernible from the attacker’s behaviors and communications."

Other key findings of the Secret Service study:

Prior to most incidents, other people knew about the attacker’s idea and/or plan to attack.

There is no accurate or useful "profile" of students who engaged in targeted school violence.

Most attackers had difficulty coping with significant losses or personal failures. Moreover, many had considered or attempted suicide.

Many attackers felt bullied, persecuted or injured by others prior to the attack.

Most attackers had access to and had used weapons prior to the attack.

In many cases, other students were involved in some capacity.

Despite prompt law enforcement responses, most shooting incidents were stopped by means other than law enforcement intervention. The end came through suicide in about one-eighth of the shootings.

The Secret Service researchers offered some hope. Some attack plans may be interrupted if quick action is taken when other students and teachers have concerns.

"However, findings from the Safe School Initiative suggest that the time span between
the attacker’s decision to mount an attack and the actual incident may be short. Consequently, when indications that a student may pose a threat to the school community arise in the form of revelations about a planned attack, school administrators and law enforcement officials will need to move quickly to inquire about and intervene in that plan."

Expert suggests team approachWhat could school officials do?

In an interview Wednesday, Fein offered several suggestions:

Disseminate clear descriptions of behavior that is and is not acceptable. Codes of conduct can help.

Create a system that can deal both formally and informally with any concerns that are raised. As an example, Fein said that schools could link dormitory residential advisers, peer counselors and health care practitioners with campus police and department heads, among others. Many systems will need some outside expertise on occasion for assessment and management.

Strengthen training and networking for all these participants in a coordinated response.

Initiate more active investigation when someone is raising concerns. If people on campus were concerned that Cho was dangerous, did he have a gun?

What about the parents?

"Federal privacy laws make calling the parents really difficult," Fein said. "But there are always ways to have a team assess what is reported by the bystanders, and devise a way for someone to come in for some level of consultation."

Students could be told, "You are scaring some people on campus who know you,” Fein said. “... We would like to talk with you about how things are going. ... I will drop by the dorm every evening at five. ... Your work seems to have dropped off suddenly. ... Your behavior is seen as unreasonably disruptive. ... We are concerned about you."

Educational institutions, Fein said, need standard protocols about when and how they will assess problematic behavior and when they might require people to take time off.

Spelling out ‘unacceptable behavior’ "Unacceptable behavior and even criminal behavior happen all the time — everywhere, in all societies and all kinds of organizations," Fein said. "People who are planning bad behavior often communicate something to people around them, by talking or e-mailing or behaving in a manner that concerns others — all the stuff this kid was doing that raises questions."

At Virginia Tech's English Department, Lucinda Roy said she made a repeated effort to talk Cho into going for counseling.